Even if you’re not an arachnophobe by nature, the half-human, half-spider nightmare that skitters into frame in the “Playtest” episode of Black Mirror‘s third season may have you thinking twice before you roll up a newspaper to tangle with that arachnid in your basement.

Conjured into being by the special effects artists at the Painting Practice, an England-based VFX house, and the London branch of Framestore, this horrific creature makes its appearance halfway through the episode, which takes place in an immersive virtual world designed by a video game company. A financially-challenged American, Cooper (Wyatt Russell), has volunteered to be a human guinea pig for this simulated reality, and as the game unfolds, he’s increasingly unable to tell the difference between its world and ours.

Black Mirror‘s VFX team picked “Playtest” as their Emmy submission in the Special Visual Effects category, and share some of the episode’s secrets in the above video, narrated by Framestore VFX producer Christopher Gray. “The episode seeks to explore the line between the virtual and the real, leaving viewers to question their own understand of the evolving difference between the two,” Gray says, referencing themes that the cult sci-fi series, created by Charlie Brooker (who also wrote “Playtest”), often explores.

To that end, the episode blends full CGI creations, like that monstrous spider-human hybrid, with select organic effects as glimpsed in a later scene where Cooper wrestles with a virtual version of a female acquaintance (Hannah John-Kamen), whose face he rips off. As Gray explains, the latter sequence features a “unique visual effect created specifically for the show. The handful of shots artfully combine organic and digital effects in a way that feels logical within the context of the scene, and yet give indication of an additional unknown reality.”

Read on for a list of the Emmy-eligible artists who worked on “Playtest,” and watch the mindbending episode in full on Netflix.